BMC 'B' Series Roller Rockers
Apart from the increased lift ratio, this new set-up is a major departure
from the traditional BMC design.

The standard rocker posts, shaft and
rocker assembly are replaced by a substantial ‘girdle’
incorporating a restricted oil feed to each rocker arm (refer Note 1).

This ‘girdle’ bolts onto the head
with 4 new head bolts and 2 new inter. bolts (supplied) once the
existing studs have been removed.
Onto this is bolted individual
rocker arm assemblies.
Each rocker arm is fully machined from
heat treated certified aircraft alloy extrusions.
Fitted with
large needle roller bearings mated to precision ground trunnions
to reduce friction and increase engine power. Roller tips
minimise valve stem and guide wear and give smoother, quieter
operation (and can’t all ‘B’ Series stand improvement in this
area ???).
Correct geometry improves efficiency by ensuring the
intended camshaft lift is transferred.
A giant step towards achieving our
aim of rigidity and a reduction of reciprocating mass in the
valve gear.